Currently, APrON collects data using traditional paper questionnaires mailed out at regular intervals throughout pregnancy and as children develop over the first 3 years. At some time points, participants are also asked to attend a clinic where biological samples and physical measures are taken. The questionnaires are long and complex (whether a question needs to be answered is dependent upon responses to previous questions) and have been identified as a major time burden by study participants. In a recent survey of 1763 APrON participants, almost 65%, indicated they would prefer to complete study questionnaires via the internet - most of the remainder had no preference. Completion rate for paper questionnaires is approximately 85% when participants come to a study clinic for an in-person visit. However, when a clinic visit does not accompany the mailed questionnaires (questionnaires are completed at home and returned by postage paid envelope) response rates are ~ 65%.